The broad objectives of this project are to contribute to the nation's capacity to produce pedigreed, specific pathogen free (SPF) rhesus monkeys (Macaca mulatta) for AIDS-related research by maintaining a production colony of Indian-origin rhesus monkeys that are SPF for SIV, SRV, STLV-1, and herpes B virus; and to fulfill specific AIDS-related research needs by providing monkeys characterized relative to MHC genotype. The specific aims are as follows: 1. To make 60-70 pedigreed SPF rhesus macaques available for research annually; 2. To maximize the value of the animals for AIDS-related research purposes by characterizing them for selected MHC Class I alleles; 3. To maximize the long term efficiency of colony production by continuing to genetically and reproductively manage the colony. During the next grant cycle, the colony will maintain a steady state of approximately 415 animals, including 160 potential breeder females, 40 potential breeder males, 110 juveniles available for sale or for use as replacement breeders, 15 adult stock animals available for assignment to protocols, and 90 infants, enabling a continuing annual harvest of 60-70 animals suitable for AIDS-related research. Testing of viral status will be conducted at the SNPRC using the Luminex platform. MHC typing will be conducted at the University of Wisconsin MHC Typing Laboratory using single specific primer-polymerase chain reactions (SSP-PCRs). During the new grant cycle, the panel of 20 microsatellite polymorphisms currently used for parentage determination will be replaced by single nucleotide polymorphisms (SNPs), which will be used to establish and verify pedigree information. The SNPs, which will be typed at the SNPRC, also will be used to confirm that all of the monkeys are of Indian origin. The SNP marker panel, along with demographic records, will be used to establish and verify pedigree information, and to manage breeding in order to avoid inbreeding and to maintain genetic variability, while focusing on the primary goal of maximizing production and harvest by utilizing data on fertility and fecundity from the colony. Fulfillment of the aims of this project will contribute to ensuring that the nation's supply of SPF Indian-origin rhesus monkeys is sufficient to meet the needs dictated by the NIH-supported AIDS-related research program.